Floor-sanding apparatus



May 23, 1950 G. F. DWYER 2,598,452

FLOOR-SANDING APPARATUS Filed May 10, 1945 4 Sheets-Sheet 1 May 23, 1950 G. F. DWYER 2,508,452

FLOORSANDING APPARATUS Filed May 10, 1945 4 Sheets-Sheet 2 I I n in i I' l Q) U U 4 1 May 23, 1950 G. F. DWYER FLOOR-SANDING APPARATUS 4 Sheets-Sheet 3 Filed May 10, 1945 S a. n

y 1950 G. F. DWYER 2,508,452

FLOOR-SANDING APPARATUS Filed May 10, 1945 4 Sheets-Sheet 4 Patented May 23, 1950 UNITED STATES PATENT OFFICE 15 Claims.

This invention relates to floor sanding machines, and more particularly to a device having a pair of power-driven sanding drums, one at each side of the machine, the drums being supported from the center of the machine so that they may work up close to the walls of a room or the like which would not be true if they were supported at their outer ends.

It is often found that floors, while apparently even and level, are, in fact, uneven and, in this event, the surface of the sanding drum which is usually cylindrical in shape will, if the drum is rigidly supported, not follow the surface of the floor but will very often be held above the floor surface and hence not perform the desired smoothing operation. I contemplate in the present invention supporting the sanding drums so that they are not only rotatable about their axes but also each is mounted to pivot or swing about an axis transverse to its axis of rotation. Each drum, therefore, in effect, is floating so that it may accommodate itself to any unevenness in the floor which may be encountered.

It is also a characteristic of the device of the present invention that the drums are driven in opposite directions so that the tractive effort-of the drums when in contact with the floor will be equalized; This not only avoids an undesirable strong pull'upon the machine in one direction or the other depending upon the direction of rotation of the drums, but also,- by arranging the drums so that the pressure on the floor may be varied individually-for each drum, this tractive eifort 'which' tends to draw the machine along the floor may be controlled so that it is exerted either in a backward or forward direction. That is, if it is desired for the machine to progress forwardly over the floor, the drum which is rotated in the direction to bring about this movement will be adjusted so that its pressure on the floor will be greater than that of the other drum.

To these and other ends the invention consists in the novel features and combinations of parts to be hereinafter described and claimed.

In the accompanying drawings:

Fig. 1 is a side elevational view of a floor-sanding machine embodying my improvements;

Fig. 2 is a top plan view of the machine;

. Fig. 3 is a sectional view on line 3-3 of Fig. 1; i

Fig. 4 is a sectional view on line 44 of Fig. 1; Fig. 5 is a sectional view on line 5-5 of Fig. 2; Fig. 6 is a rear elevational view of the handle and controlling levers;

Fig. 7 is a sectional .view on line l-I of Fig. 6;

Fig. 8 is a rear elevational view of the block upon which the adjusting handle is mounted;

Fig. 9 is a sectional view on line 99 of Fig. '7;

Fig. 10 is a sectional view on line Ill-I0 of Fig. 2;

Fig. 11 is a partial plan view partly in section of a modified form of sanding drum;

Fig. 12 is a transverse sectional view through the sanding drums; and

Fig. 13 is a sectional view of the upper end of thehandle of the device showing a steering mechanism of modified form.

As illustrated in the drawings, I have shown a frame H), which comprises a fan casing H and a pair of spaced forwardly projecting tubular members I2, these tubular members being formed integrally with the fan casing H, and forming pivotal supports for the sanding drums as will be hereinafter explained. Within the fan casing l l is mounted the usual fan l3 secured upon a shaft 14, this shaft extending through the upper side of the casingwhere, upon its extended end, is

mounted a pulley l5. A belt [6 is trained about this pulley and also about a pulley IT on the shaft 18 of an electric motor I9, the motor casing being supported from the fan housing as shown in Fig. 1. The pivotal support of the drums is shown more especially in Figs. 3, 4 and 5 and, as the arrangement of one drum is identical with that of the other, a description of one will suffice for both. The tubular member I2 is split for a short distance from its open end as shown at 2| and, within this member, is slidably mounted a sleeve 22, and within this sleeve is rockably mounted a trunnion 23, the trunnion being secured against longitudinal movement with respect to the sleeve by reason of its flaring outer end 24 and a nut 25 threaded into the trunnion at its inner end and abutting the rear edge of the sleeve. This trunnion may, therefore rock about its longitudinal axis with respect to the sleeve 22 and, therefore,

with respect to the frame of the machine, and it may also be moved longitudinally of the tubular frame member 12 with the sleeve 22. In order to clamp the sleeve 22 against movement within the split tubular member l2, a pair of clamping The trunnion 23 is formed integrally with the support 28 of the standing drum, which support is generally of cylindrical shape as shown at 29, and comprises a hollow dust-collecting chamber 30, the walls of which are, however, discontinued as shown at 31 to permit contact of the drum with the floor. The drum support is also provided with a bearing member 32 which rotatably supports the shaft 33 of the sanding drum 34, the latter also being" cylindrical in shape and mounted within the cylindrical portion of the drum support 29.

As shown more especially in Fig. 3, mounted upon the exterior of the drum, is" a pneumatic tire 35 which carries the endless sanding belt or web 36. The member 35 may be collapsed, and the sanding belt 36 may be slipped over the edge of the drum and, thereafter, the member 35 may be inflated so that the belt will grip this portion of the drum tightly. 'On the inner end of each of the shafts 33 is a'pulley 31-, these pulleys being slightly spacedapart but beingrelatively close together so that there will be littlegap between-the trained around a pulley. 40 secured to the lower end of the fan shaft I4. The intermediate portions of the runs of the belt 39 are trained about the pulleys 31 attached to the shafts 33 of the sanding box so that, as will be apparent, one of these drums is driven in a direction opposite to the other drum. It will also be noted that each end of the belt 39 is positively driven, one endb'y the pulley 38 directly upon themotor' shaft, and

the other end by the pulley 491115011 the fan shaft which is, in turn, driven by the puney l from the motor shaft.. This will equalin'e the tension upo n the belt 39 so that there will be no slack side of this belt and drive the drums evenlyso as'to bring about an even sandingof the floor.

It may also be noted that, asshown in Fig. 2, the belt t6 is crossed between'the'pulley's I5 and f1 's'o'th'at the pulley 40 will be'driven inthe proper direction. I

As the drums rotate; the dust "from the floor will be thrown in the direction of rotationand will enter one or the other of the open endsof the casing '30, depending uponthe direction of rotation. The dust will bedrawn through the hollow trunnion 23and'thesleeVe1-2 into the fan 'casing 13 from which it will be expelled through the tubular member 43 and collected in the dust bag 44, the bag beingremovable, as hereinafter described, for emptying.-

To the rear end of thefan housing l3 issecured a frame 45 within which is rotatably mounted the shaft 46 of a caster wheel designed to support the rear end of the device. Also secured to the frame 45 is a handle member 48 provided at its upper end with a crossbar 49. This handle member is hollow, and extending therethrough is a steering rod 56 connected through a universal joint 5| to the steering wheel shaft 46, the upper end of the rod 50 being provided .with a handle member 52 by which it may be rotated to effect rotation of the shaft 46 of the steering wheel, so

that the frame may be steered in its movements over the floor.

It is' also contemplated thattheposition's' of the" drums relatively to the fioor'niay be adjusted and that this adjustment may be made simultaneously for both drums or individually for each drum, so that one drum, if desired, may contact the floor with greater pressure than the other. Also, the arrangement is such that the pressure of the drums upon the floor may be regulated by means of springs, which springs, as will be hereinafter explained, tend to counteract the Weight of the drums or the forward part of the machine and so control the position of the drums with respect to the frame.- I

To this end, a pair of levers 55 are pivotally secured at 56 to the ends of a cross bar 51 carried by the lower clamp member 26 (Fig. 4). Upon each of these levers is mounted a supporting wheel 58,. which wheels bear upon the floor and constitute fulcrums upon which the forward end of the framemay be raised or lowered by the levers. The two levers 55 extend rearwardly and upwardly as shown in Fig. 1 so as to constitute a yoke, the upper ends being bent inwardly and connected-respectively to the ends die member 69 by universal or ball a-nd-socket'joints '6F. member 30 is disposed above an arcuate- -shaped retaining member '62 secured to the hanmennem ber 48', whichmern'ber curvedabout the pivot "point as of the levers. The member 6 2' may-Be provided with a notch i53 "vvi'thi'n:w'hi'clf theed'ge of the member 69 maiy'eng'ag'e -ahd be retained when the drums arelifted from the floor.

It will be apparent that with the above construction, when the b-lo'ckewis moved forwardly and rearwardly over the member" 62',- the pivot point 56 will be lowered and raised: respectively with respect'to the supporting'wheels 58 and-will, therefore, raise and lower the sanding drums with respect to these wheels, and that the member 63 is at a position where it may: readily be adjusted by the operator inorder to adjust the pressure of the drums on the floor. Also, due to the ball-and-socket connections 6! between the member 6e and thelevers 55, thismember may be tilted with respect to thesupport 62 and thus raise one of the sanding drums while lowering the other due to the fact that one of the levers 55 wi1l be raised while the other is lowered.

The means forcounterbalancing the pressure of the drums on the floor and holding" the levers 55 in adjusted position is shown more particularly in Figs. 1, 6' and '7'. To each of the levers 55 is secured a tension spring 65,. the ends of these springs being secured at the opposite sides of a plate 66 pivoted to a block '61. This block is 'slidably mounted on the handle by means of a plate 68' secured to the handle, which plate is received in a channel shaped recess '69 in the back of the -block.- At the lower edges of the block, inwardly projecting ears or lugs 70 are provided to engage the rear face of the plate 68 and hold the block" thereon. The plate 68 is provided with a series of teeth H, while the block '6! is provided with a single tooth or pawl 12 to engage therewith. By reason of the fact that the lugs '10 are provided only at the lower portion of the block, the upper end of the latter may be swung outwardly from the plate 68 to disengage the pawl T2 froh'i'the teeth TI so that the block may be adjusted with respect to the plate, thus adjusting the tension of the springs With this arrangement, if it is desired that the" drums bear oniy lightly on the floor, the block is moved downwardly with respect to the plate 68', thus increasing the tension of the springs 65', which tends to p'ul'lthe levers 55 downwardly and raise the pivot points 56' with"respect to the caster or floor-engaging wheels 58. 'Thusany desired pressure for the drums upon the floor may be provided.

Secured to the plate 66 is an upwardly projecting handle I4 which is pivoted to the block 61 by means of the bolt I5. This bolt is threaded into the block 61 and carries a nut I6 and spring washer II to secure the plate 66 and handle I4 in place. By this arrangement the plate 66 may be tilted about the axis of the pivot bolt I by means of the handle I4. The tilting of the plate 66 will elongate one of the springs 65 andperput the length of the other to decrease so that there is more tension on one of the springs than on the other, which will in turn cause one of the sanding drums to exert a greater pressure on the floor than the other. Thus by swinging the handle I4, the pressure of either drum upon the floor may be varied with respect to the other drum so that the machine will tend to move backwardly or forwardly as desired as the drums rotate in opposite directions, and the friction oi the sprin washer 'I'I will be suflicient to hold the handle in adjusted position.

It may be noted that the fan casing l I is divided by a partition 89 into an upper fan chamber BI jects forwardly from the fan housing II and extends between the sanding drums 86 and 81. These sanding drums are similar to those pre- -viously described in that the abrasive band will be mounted thereon in the same way and, likewise, each is provided with a surrounding dusteollecting housing 88 communicating with a tubular member 89 connected by a flexible coupling 90 such as a rubber tube, for example, to conduits 9| which lead into the lower chamber of the fan housing. The coupling members 90 will permit slight pivotal movement of the sand ing drums so as to permit these members to follow any unevenness in the floor.

Each of the sanding drums is rotatably mounted upon an axle 92 by means of ball bearings 93, the outer bearings being held in place by cap nuts 94 which may be turned up against lock'nuts 95 within axles 92 which are hollow.

Projecting from each side of the central frame member 85 are spindles 85 which extend within the hollow axles 92, and the axles :are pivotally secured to these spindles adjacent the outer ends thereof by wrist pins 96 permitting the axles a pivotal movement about these pins, the axis of which movement is transverse to the axis of rotation of the sanding drums. The dust-collecting housing 88 may be secured to the axles by means of webs 91 and screws 98.

Secured to the drums are pulleys 99 around which may be trained the belt I00 leading to a pulley IUI on the motor shaft as before. a

In Fig. 13 of the drawings I have shown a slightly modified form of device for steering the rear caster 41 which provides for lockin this caster in a given position. In this instance, the

'rod 50 extending through the hollow handle "member 48 is provided with a collar I02, the

outward movement of which is limited by set screws I03. At its upper end, the rod is of polygon-a1 shape as at I04, and slidably mounted thereon is the steering wheel I05. This wheel may be held in place by a clampingspider I06 having a stem I01 threaded into the steering rod.

It will be seen that when the spider I06 is screwed down tightly upon the steering wheel I05, the latter is clamped against the end of the handle member 48, and the caster wheel 41 will then be clamped in any desired position to act as a stabilizer and oppose any tendency of the frame to swing in one direction or another due to the friction of the drums with the floor. The spider I06 may be backed off to any extentdesired, so that the caster wheel will be completely free or will be under the desired amount of friction. .As the steering wheel I05 is non-rotatably mounted on the steering rod 50 due to the complemental polygonal shapes of these parts, it will always serve to turn the steering rod, even when the spider I06 is loose.

Baflies H0 are provided within the dust-collecting chambers 30 so that the suction through the tube 23 will not be divided but will be exerted in one direction about each of the sanding drums. The position of the baflies will depend, of course, upon the direction of rotation of the drums. As shown in Fig. 5, it is assumed that the drum is rotating in a counterclockwise direction, and, hence, the bafile will be upon the upper side of the tube 23 so that the force of the I suction will be exerted about the lower side of the drum. As the drum on the other side will rotate in the opposite direction, the baflle will be located below the tube 23, so that the suction would be drawn from the upper side of the drum.

1 The dust bag 44 may be removably secured in any suitable manner to a rigid base plate III. To this base plate is secured a tube H2 which is designed to telescope over the tube 43 so as to hold the base plate I I I in place. Within the tube H2 is secured a second tube H3 of the same diameter as the tube 43, so that the lower end of the tube I I3 will abut the upper end of the tube 43 and thus support the bag from below. With this construction the bag and base plate I II may be readily removed from the tube 43 and the bag removed from the base plate for emptying. When replaced with the tube H2 telescoping over the tube 43 as far as permitted by the engagement of the upper end of the tube 43 with the lower end of the tube H3, the bag will be rigidly held in position without other securing means.

While I have shown and described some preferred embodiments of my invention, it will be understood that it is not to be limited to all of the details shown, but is capable of modification and variation within the spirit of the invention and within the scope of the claims.

What I claim is:

1. In a floor-sanding machine, a wheeled frame, a cylindrical sanding drum, means mounting said drum on the frame for rotatable movement about its axis and for swinging movement about an axis transverse to the axis of rotation, means for driving said drum, said driving means including an endless belt having its intermediate portion drivingly engaged with said drum, and driven pulleys around which both bight portions of the belt are trained.

2. In a floor-sanding machine, a frame, a pair of substantially cylindrical sanding drums, means rotatably mounting said drums on said frame member, a cross bar to which the upper ends of said levers are pivoted, a member on the handle upon which said cross bar is movably supported whereby the latter may be moved toward and from said handle member to adjust the pressure of the drums on the floor, a spring member connected to each of said levers and connected to said handle member to resiliently support the drums, and means for adjusting the tension of said springs relatively to each other to variably adjust the pressure of the drums on the floor.

11. A floor-sanding machine, comprising a frame having a forwardly extending portion, spindles projecting laterally from said portion, axles pivotally mounted on said spindles, sanding drums rotatably mounted on said axles, the axis of said pivots being transverse to the axis of rotation of the drums whereby the latter may rock about the spindles, and said frame portion being tapered from its central portion outwardly to permit rocking movement of the drums.

12. A sanding machine having a frame, sanding drums rotatably mounted thereon, wheel supports for said frame including a steering wheel, a handle upon the frame, a steering rod connected to the steering wheel and extending upwardly through the handle, and means for frictionally securing the steering rod to the handle to hold the steering wheel in a predetermined position.

13. In a floor-sanding machine, a wheeled frame, a pair of substantially cylindrical sanding drums, means rotatably mounting said drums for rotatable movement with their axes in alignment and for swinging movement about horizontal axes transverse to the axes of rotation, means for driving said drums, including an endless belt having its intermediate portion drivingly engaged with said drums, driven pulleys around which both bight portions of the belt are trained, and the portion of said belt between said pulleys and the drums being substantially parallel to the floor when the machine is in operation.

14. In a floor-sanding machine, a frame, a pair of substantially cylindrical sanding drum's, means mounting said drums on the frame with their axes in alignment, a steering wheel on said frame, a handle member by which the frame is controlled, a pair of arms, each having a pivotal connection with the frame, a floor-engaging )fulcrum, and means mounted on the handle members and connected to said arms to adjust the same to vary the position of the drums with respect to the floor.

15. In a floor-sanding machine, a frame, a pair of substantially cylindrical sanding drums, means mounting said drums on the frame with their axes in alignment, a steering wheel on said frame, a handle member by which the frame is controlled, a pair of arms, each having a pivotal connection with the frame, a floor-engaging fulcrum, and means mounted on the handle members and connected to said arms to adjust the same to vary the position of the drums with respect to the floor, said means being arranged to move said arms relatively to each other and thereby adjust one drum relatively to the other.

GEORGE F. DWYER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 794,305 Lyon July 11, 1905 876,155 Edlund Jan. 7, 1908 907,058 Kraemer et al Dec. 15, 1908 939,363 Whatley Nov. 9, 1909 992,730 Allen May 16, 1911 1,248,157 Piper Nov. 27, 1917 1,255,230 Roese Feb. 5, 1918 1,386,539 Strock Aug. 2, 1921 2,116,272 Mall May 3, 1938 2,224,437 La Salle Dec. 10, 1940 

